Filter syringe

ABSTRACT

A syringe for the injection of liquid having a diaphragm sealing the open end thereof and a filter member between the diaphragm and the open end of the vial with a hollow needle mounted for reciprocal movement between retracted position beyond the diaphragm and operated position piercing the diaphragm but not piercing the filter member.

United States Patent 11 1 Rovinski 1 51 Sept. 11, 1973 [54] FILTERSYRINGE 2,807,288 9/1957 Shea 128/272 X 2,628,615 2/1953 Saffir 128/272x [75] Inventor: Walter M. Rv1nsk1,Turnersv1lle, 1,943,120 1934 Kabnick128mg M 3,557,787 1/1971 Cohen 128/218 M [73] Assignee: CenturyLaboratories, Inc., Metairie,

La. Primary Examiner-Richard A. Gaudet Assistant Examiner-J. C. McGowan[22] Flled' May 1971 Attorney McDougall, Hersh & Scott [21] Appl. No.:146,271

, [57] ABSTRACT [52] U.S. Cl. 128/218 M, 128/220 51 1m. (:1 A6lm /00 ASyrmge for the miectlon of llqwd havmg a dlavhragm 58 Field of Search128/218 M, 272, 21s 1), Sealing the p end thereof and a filter member zgz g NV, 13 R 21 2 2 tween the diaphragm and the open end of the vialwith a hollow needle mounted for reciprocal movement be- 5 ReferencesCited tween retracted position beyond the diaphragm and op- UNITEDSTATES PATENTS erated position piercing the diaphragm but not piercing 1the tilt mb 3,682,315 8/1972 Haller 128/272 X er me er 2,778,360 11/1957 Miskel 128/218 D 1 Claim, 2 Drawing Figures 3,592,245 7/1971Schneller et a1. 128/272 2,854,977 10/1958 McConnaughey 128/2723,255,752 6/1966 Dick 128/218 M .AJ: r 2 is x 35 30 3/ 1 1 2'7 1 l i 2 gI \l a9 1 FILTER SYRINGE This invention relates to syringes for theinjection of solutions and it relates more particularly to a syringe inwhich the solutions are effected therein immediately prior to injectionby bringing the liquid solvent into contact with the solute in liquid,solid or powdered form.

In the recently issued Cohen US. Pat. No. 3,557,787, description is madeof a disposable syringe formed by telescoping tubular members in whichthe inner tubular member of smaller dimension is adapted to contain aliquid solvent and the outer tubular member of larger dimension isadapted to contain the liquid, powdered or solid material in measuredamounts for solution to provide a desired dosage.

The inner tubular member is provided with a flexible seal to separatethe two chambers and which is adapted to open in response to pressuregenerated by a piston member displaceable in the inner tubular member toeffect transmission of the liquid from the inner tubular member to theouter tubular member. The end of the inner tubular member sealablyengages the inner wall of the outer tubular member and functions as apiston to force displacement of the solution from the outer tubularmember into the needle in communication therewith for injection.

It has been found that often times complete solution of the powdered orsolid material is not effected with the result that solids remainsuspended thereby to represent a foreign material in the solution whichit is undesirable to include with the liquid injected.

Similarly, in syringes that have been pre-packaged and sterilized with asolution or liquid to be injected from a single container, often timessolids form by reason of decomposition, reaction or otherwise uponstanding thereby to represent a foreign material which it is undesirableto include with the solution or liquid that is being injected.

Thus it is an object of this invention to provide a syringe for theinjection of liquid or other solution and which embodies means for theremoval of solids contained or otherwise suspended therein as the liquidis being ejected from the syringe.

These and other objects and advantages of this invention willhereinafter appear and for purposes of illustration, but not oflimitation, an embodiment of the invention is shown in the accompanyingdrawing in which:

FIG. 1 is a schematic sectional elevational view of a sryinge embodyingthe features of this invention in normal position of use; and

FIG. 2 is a sectional elevational view showing the arrangement ofelements during ejection of fluid from the needle end portion of thesyringe.

Referring now to the drawing, the fluid to be injected is illustrated asbeing contained in a vial l2 having an open end 14 formed with a neckportion 16 which terminates in an outwardly extending angular flangeportion 18. The fluid 10 is maintained in sealing relation within thevial by means of a diaphragm of rubber or plastic material which isdimensioned to span the opening and extend therebeyond for a distancecorresponding to the neck flange 18 of the vial. The diaphragm 20 isclamped in sealing relation on the end of the vial by means of a metalcup 22 which is crimped about the outer flange portion of the neck andthe corresponding outer edge portions of the diaphragm 20 to effect asealing engagement between the adjacent flattened outer end portion ofthe neck flange l8 and the diaphragm 20, when in the assembled relation.The cup member 22 is formed at its outer end with an inwardly extendingannular flange 25 and compressed within said cup resiliently to engagethe annular flange is a compression spring 26 which is wound about aneedle hub 27having a disc member 31 of larger dimension which functionsas an abutment for the opposite end of the spring. The main outwardportion of the hub is formed with threads 29 for threaded engagementwith internal threads of a needle cover 32.

The hub member supports a hollow needle 28 which is mounted for endwisemovement between a retracted position in which the inner sharpened endportion 30 terminates just short of the diaphragm 20 and an operatedposition in which the needle is displaced inwardly to a position whereinthe inner sharpened end portion 30 of the needle penetrates thediaphragm for direct communication with the interior of the vial toenable ejection of fluid from the vial through the needle. Reference maybe made to U. S. Pat. Nos. 3,557,787 and No. 3,401,693 for means formounting the needle releasably to retain the needle in retractedposition for releasing for movement to operated position in response toremoval of the needle cover 32. in the modification illustrated in FIG.1, the coil springs 26 operate immediately to effect displacement of theneedle from retracted to operated position in response to removal of theneedle cover which releases the hub.

In accordance with the practice of this invention, direct communicationbetween the needle and the interior of the vial containing the liquid tobe ejected is obstructed by a filter member 34 in the form of a filterdisc which extends crosswise between the flanged open end portion of thevial and the diaphragm to span the open end of the vial and for sealingengagement between the clamped flanged neck end portion 18 of the vialand the diaphragm 20, as by heat sealing to the upper surface of thediaphragm. The filter disc can be formedof ceramic, paper, plastic,rubber, glass or the like material having communicating fine pores forthe removal of solids from the liquid passing therethrough but withoutobstructing fluid flow, such as filter pores of 0.1 to 1 micron andpreferably about 0.2 to 0.4 micron.

In order to permit needle penetration of the diaphragm 20 withoutpiercing the filter disc 34, the diaphragm is dimensioned to have athickness whereby the inner wall 36 is spaced inwardly from the end 30of the needle when the latter is in operated position. A well 38 isprovided to extend through the central portion of the diaphragm from theinner wall in endwise alignment with the needle to a depth sufficient toprovide for entrance of the needle end 30 when displaced to operatedposition. Thus, the diaphragm 20 is effective to maintain the sealedrelationship to seal the liquid in the vial while enabling penetrationof the needle into the well for communication with the interior of thevial when in operated position. The filter element 34is in positionbeyond the end of the needle to separate the well from the interior ofthe vial whereby all liquid entering the well for ejection through theneedle is required to pass through the filter element.

Operation of the invention will be described with reference to a syringeof the type illustrated in U. S. Pat. No. 3,557,787, although it will beunderstood that the inventive concepts may be adapted to a syringe inwhich the liquid to be injected is housed within a single vial having apiston member adapted to force the liquid from the vial.

In the modification which is shown in FIG. 1, when it is desired toeffect injection of a measured amount of liquid from the syringe, thepiston 44 in the inner vial 42 is displaced endwise to force the liquid40 for displacement through the flexible sealing diaphragm 46 from theinner vial to the outer vial 12 containing the powder 48. The vials arethen shaken to dissolve the powder or other solid material or to mix thetwo different liquids in the event that one vial contains one and theanother the other. When the solution has been effected and the injectionis to be made, the needle cover 32 is removed. This releases the needle28 which is actuated by the tension springs 50 for displacement fromretracted to operated position during which the end 30 of the needlepierces the thin wall of the diaphragm for entrance of the needle intothe well 38.

Thereafter, the inner vial 42 is displaced in the illustratedmodification to eject the liquid from the outer vial 12. This forces theliquid to flow through the filter element 34 to fill the well 38 andfrom the well to the needle 28 for injection as pressure continues to beplaced on the liquid in the vial. Solids 52, which remain suspended inthe liquid, are separated out on the ingoing side of the filter surfaceas the liquid flows therethrough thereby to deliver a filtered fluid tothe needle 28.

It will be understood that the concepts of this invention will haveapplication to syringe devices formed of but a single vial in which aliquid material is contained for injection with the filter element anddiaphragm arranged in the manner heretofore described.

It will be understood that changes may be made in the open end of thevial in sealing relation therewith,

a hollow injection needle having inner and outer pointed ends endwisealigned with the open end of the vial and mounted for endwise movementbetween retracted position with the inner end of the needle spaced ashort distance beyond the diaphragm and operated position with the innerend of the needle piercing the diaphragm, the improvement whichcomprises a filter member spanning the open end of the vial between theend of the vial and the diaphragm, said diaphragm constituting a memberseparate and apart from the filter, a well in the diaphragm extendingfrom the side adjacent the filter member partially through the diaphragmin endwise alignment with the needle and into which the inner end of theneedle extends when in operated position and stop means mountedintermediate the needle ends, whereby in the operated position the innerneedle end will extend through the diaphragm but not pierce the filter.

1. In a syringe for the injection of a liquid including a vial having anopen end through which the liquid is to be ejected from the vial and aplunger axially displaceable in said vial for displacement of liquidthrough the open end, a rupturable diaphragm extending across the openend of the vial in sealing relation therewith, a hollow injection needlehaving inner and outer pointed ends endwise aligned with the open end ofthe vial and mounted for endwise movement between retracted positionwith the inner end of the needle spaced a short distance beyond thediaphragm and operated position with the inner end of the needlepiercing the diaphragm, the improvement which comprises a filter memberspanning the open end of the vial between the end of the vial and thediaphragm, said diaphragm constituting a member separate and apart fromthe filter, a well in the diaphragm extending from the side adjacent thefilter member partially through the diaphragm in endwise alignment withthe needle and into which the inner end of the needle extends when inoperated position and stop means mounted intermediate the needle ends,whereby in the operated position the inner needle end will extendthrough the diaphragm but not pierce the filter.